Fluid Components International FLT Series Rack Mount - Manual (Page 36)

Doc. No. 06EN003250 Rev. N/C 3 - 1 FLT  Series FlexSwitch  Rack Mount
CHAPTER 3 - OPERATION FLUID COMPONENTS INTL
3. Operation
Factory Default Configuration
Unless a custom factory setup or calibration is specified, the FCI instrument is delivered in a standard factory default
configuration. The standard configuration is shown in Table 3-1.
Table 3-1. Standard Default Configuration
Input Power 24VDC.
Heater Power 0.75 Watts for air flow or liquid level applications (CH A, J5; CH B, J31).
Numer of Alarms Two (CH A, J18; CH B, J44). Each alarm has one set of SPDT contacts.
CHANNEL A
Alarm 1
Red LED
Set Point Pot. R30
Set to monitor flow or level signals (J14). Relay energized at flow or wet
(J21). Set point at approxinately 10 to 15 sfps decreasing flow.
Alarm 2
Green LED
Set Point Pot. R29
Set to monitor temperature signals (J15). Relay energized below
temperature (J19). Set point at approximately 240 ±5°F (115 ±3°C).
CHANNEL B
Alarm 1
Red LED
Set Point Pot. R58
Set to monitor flow or level signals (J40). Relay energized at flow or wet
(J47). Set point at approxinately 10 to 15 sfps decreasing flow.
Alarm 2
Green LED
Set Point Pot. R69
Set to monitor temperature signals (J41). Relay energized below
temperature (J45). Set point at approximately 240 ±5°F (115 ±3°C).
If the order included custom factory setup and calibration, leave all settings alone. The instrument should be ready
for service without changes.
If the custom factory setup or calibration was not ordered, configure the control circuit using the configurable jumper
tables below and then follow the set point adjustment section that is appropriate to the application.
Configuration Jumpers
If the order did not specify for the control circuit to be factory configured, the standard configuration can be changed
using Figure 3-1 and Table 3-2 though Table 3-6. The factory default configuration is shown as being underlined.
Heater Cut-Off
The control circuit has a heater cutoff switch that limits the temperature of the sensing element to a temperature
differential of approximately 150 °F (66 °C) above the process temperature. In the case where the instrument is used
as a gas flow switch, and the heater wattage is set too high, the temperature differential (
∆
T) between the RTDs may
exceed the usable input range of the control circuit. The usable input range can also be exceeded in the case where
the instrument is used in liquid flow applications where the heater wattage is set at the highest value, and when the
sensing elements go dry. When the temperature differential is less than 150 °F (66 °C) the heater automatically turns
back on.
The reason for operation in the above extreme conditions is that the input signal range is at the widest point making
the alarm set point adjustment easier to perform. If the heater does cycle the operator may need to use the next lower
wattage setting.
It is possible to use one of the alarms to detect when the heater is being shut down because of an over-range situation.
The alarm must be set to activate with flow/level signals.